Volunteer opportunities in Hanoi

Hello

I am teaching and living in Hanoi and I would like to know if there are any opportunities to volunteer to help underprivileged children. I'm currently working in an international school and I would like to contribute to the lives of the wider community.

I would like to volunteer during the week for an evening and not during the weekends. I will be able to commit to 5months of volunteering.

I have only been able to find gap year style volunteer placements so far that offer placements for 2weeks to 6months full time. Where as I am looking to commit to a few hours a week.

If you have any suggestions then I would love to hear from you. Thank you for your time.